ABSTRACT
Coronary artery disease (CAD) represents a global leading cause of death especially for middle- and high-income countries. In 2012, all-cause deaths were estimated as 56 million worldwide with 17.5 million deaths attributed to cardiovascular disease (CVD). The initial concept of atherosclerosis progression and plaque phenotypic change was established by Dr. Velican in the early 1980s who focused on morphological descriptions of fatty streak lesions to advanced fibroatheromatous plaques complicated by haemorrhage, calcification, ulceration and thrombosis. Numeric American Heart Association (AHA) lesion types I-IV were essentially replaced by descriptive terminology to include adaptive intimal thickening, intimal xanthoma, pathologic intimal thickening (PIT) and fibroatheroma (FA) with recognised progressive lesion morphology of early and late FAs. Intimal thickening in the absence of atherosclerosis is considered the earliest vascular change consisting primarily of smooth muscle cells (SMCs) and extracellular matrix. PIT is considered the earliest of progressive change.
